Dielectric Spectroscopy of Bent-Core Thioesters' B Phases

Banana-shaped homologoues 1,3-phenylene bis{4-[(4-alkoxybenzoyl) sulfanyl]benzoate}, in short nOSOR, where n denotes the number of carbon atoms in the end chains, have been studied using dielectric and electrooptic methods. 9OSOR shows a ferroelectric B-1 phase, whereas 12OSOR, 14OSOR exhibit antiferroelectric B-2 phase. Dielectric spectra have been measured for two alignments of B-2 phase. In the low frequency range a broad collective relaxation process is observed under bias field. This process is connected with fluctuations of ferroelectric domains. The high frequency relaxation originates from molecular reorientation around the long axis.